Generally, various forms of automatic gain control (AGC) of a signal are known. The AGC process for a received signal may allow for limiting the distortion level of the received signal before a demodulation process of the received signal. The AGC operation normally includes comparing the signal strength of a received signal to a threshold. Depending on the signal strength level with respect to the threshold level, an amplifier amplifying the received signal for a receiver processing may change the amplification level. In another aspect, the amplification process may change to attenuation of the received signal based on the received signal strength level. For proper demodulation of the signal, the receiver normally may have a filter in the signal path that filters to some degree the signals outside the frequency range of the signal carrying the received data. As a result, the received signal strength level is mainly an indication of the signal strength of the in-band signal. After the AGC processing of the signal, the signal is passed on to a demodulator for extracting the received information.
However, for receive processing of a multi-carrier signal, the front-end filter has a wide frequency bandwidth allowing for the entire band of the multi-carriers. One ordinary skilled in the art may appreciate that the demodulation process for a multi-carrier signal includes a different demodulation process for each carrier in the multi-carrier signal. As such, each carrier of the multi-carrier signal may need an independent AGC process. With a wideband filter for a multi-carrier signal, the received signal strength in the AGC process is an indication of the signal strength of all carriers in the multi-carrier signal. Therefore, there is a need for a method and apparatus for front end AGC processing of a multi-carrier signal and independent AGC process and demodulation of each carrier signal in a communication receiver.